Originally designed to mirror a British Parliamentary party [and indirect Patronage] representation system - it went askew just recently [this last decade or two] to resemble a highly oligarchical managed system that is set to favour the usual ruling classes - changed and revamped, here and there, to maintain this status quo.
Whatever it has become, it's certainly not balanced or anything resembling democratic.
Over many decades [from the 1950s/1960s], this rather unusual, and uniquely Thai, system has never been tested - as we jump from one coup and forced military rule to another.